Process for the aftertreatment of freshly-spun artificial silk



April 17, 1928. 1,666,090

F. J. GAHLERT' PROCESS FOR THE AFTER TREATMENT OF FRESHLY SPUN ARTIFICIAL SILK Filed July 28, 1926 J/rvenfor (PM 0W, M

'-duced whlch possesses special Patented 17,

UNITE]; s

FRANZ JOSE! GAHELERT, OE DRESDEN-LOSOEWITZ,

PROCESS FOR THE AHEBTREATMENT or'rnEsnLY-smm narrrrcm smx.

Application filed July 28, 1928, Serial No. 125,355, and in Germany June 9, 1925.

' This invention relates to a process for treating freshly spun artificial silk and which consists in that the thread of artificial silk is s un again in being stretched and twisted, pre erably with application of a softening means or of a solvent.

By this process quite a new thread is proroperties. If, for instance, as weft for a fa ric, artificial silk is used which has been treated accordin to this process and which has been wet-tw1sted, the weft oduces an extraordinary solidity of the abric and produces in combination with the brilliancy of the commonly used warp-silk a peculiarly watered fabric. The solidity of the new artificial silk fabric is so great that this fabric is washable, which is not the case for the hitherto known artificial'silk fabrics. This fabric is, therefore, something quite new and, owing to its extraordinary solidity, it can be dyed in the piece, which is a further advantage. Whi st artificial silk fabric of. known kind was stretched at the dyeing in. the piece, so that the fabric becomes loose and open portions were formed in the piece, just the opposite occurs with the new fabric. The fabr1c contracts'at the dyeing in the piece as the sharply twisted weft-silk contracts. This is the reason why the fabric possesses such wonderful closeness and solidity and is washable.

In the form of execution of the process illustrated in the accom anying drawlng the thread of artificial si k. is softened by a liquid, for instance water. Evidently other softening means might be used.

v I a The freshly spun thread of artificial silk is re-spun again in such a manner that it is made topass through a stretching device comprising a water trough for wet-spinning. As a thread of artificial silk is dgenerally very brittle it could not be stretche if, prior to the stretching, it would not have been softened. This softening is effected, for instance bymoistening in. the water-trough whereby the thread of artificial silk loses immediately its brittleness and becomes soft L .and supple, so that it is lengthened by the stretching cylinder owing to its stretchability, whereby a very fine and durable fabnc of artificial silk. is obtained.

Referrin to the accompanying drawiig the silk bo ins 3 are placed'on P1118 2 fix in the bobbin board 1. The silk thread dis unwound from the bobbinguided over a iATEs: IPIA'TENTYOFFICE- mersed in the water in trough 8' so that the thread is moistened before, bythe thread guide 10, it is guided to the stretching cylinder 11 around which the thread is wound. In this position the thread is pressed by the pressing cylinder 12. The thread 4 of artificial. silk oes then through the thread guide 13 to t e ring-spinning eye 14 to be wound upon the bob in 15 WhlCh is mounted on the spindle 16.

The stretching cylinder 11 rotates at higher speed-than thepulling-ofi' cylinder 6 so that the thread is stretched between these two cylinders. The brittle thread 4 of artlficial silk is made supple by being dipped into the water-trough 8 so that it becomes extensible. According to thedepth at which the thread is dip ed into the water-trough, its extensibility ecom-es greater or lesser so that it can be stretched more or'less. The

interval between dipping" point and stretch- 1ng cylinder is preferably variable so that it can be adapted to the degree of moistenin the stretched thread drying when it trave s through this interval. The resistance of the threa is then increased 'so that it doe not break at the spinning. The thread could be dried artificially- As the thread is spun at a more or less dissolved state owin to the moistening, the spun thread of arti cial silk possesses other properties which assert themselves specially at sharp twisting. The strongly twlsted thread of artificial silk, produced according to this wet-spinning process, does not form .running knots, it does not coil and it is distinguished by great durabilit and especially by the effect it produces 1n the finished fabric.

The cylinders 6, 7 supply the dry thread and the stretching cylinder 11 and pressing cylinder 12 pull the wet thread off, so that breaking of the thread can be avoided by correctly regulating the ratio of transmission in the stretching mechanism.

1. A process for treating freshly spun arin treating the thread tificial $11k consisting fie t a so mng agen m of artifici silk wit stretching the softened thread, and in re- 3. A process for treating freshly'spun artwisting this thread. tificial $11k, consisting in softening the thread 10 2. A process for treating freshly spun arof artificial silk by means of water throu h tificial silk, consisting in softening the which the thread 15 made to ass, in stretc 5 thread of artificial silk by'means of water ing the softened thread, an in submitting through which the thread is made to pass, this thread to strong twistin in stretching the softened thread, and in re- In testimony whereof I a 111 Si ature. twisting this thread. FRANZ JOSEF G RT. 

